Abstract
Soil thermal conductivity is an important indicator for developing and utilizing geothermal resources. In this study, the impact of underground environmental factors on the thermal conductivity of loess was explored by studying the thermal conductivity of saturated and unsaturated loess under varying water content, dry density, and temperature using the Hot Disk thermal constant analyzer. The results show that the thermal conductivity of unsaturated undisturbed and remolded loess presents different growth trends as the water content increases. When the water content is less than 9%, the thermal conductivity of undisturbed soil increases slowly. The thermal conductivity of unsaturated loess gradually increases with temperature. When the temperature rises above 30°C, the latent heat transfer of steam gradually strengthens, accelerating the increase in thermal conductivity, which is most noticeable at intermediate saturation. However, the thermal conductivity of saturated loess rises slowly as the temperature rises. A weighted geometric average model is proposed in this study to predict the thermal conductivity of loess under temperature conditions, considering the effects of soil water content, dry density, and mineral content. The model accuracy was corroborated by the measured soil thermal conductivity and the data collected from six regions.
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Abbreviations
- a :
-
Air
- D :
-
Diffusion coefficient of water vapor in air
- da :
-
Dry air
- H L :
-
Latent heat of vaporization
- min :
-
Minerals
- n :
-
Soil porosity
- P :
-
Pressure
- q :
-
Quartz
- s :
-
Solids
- Sr :
-
Saturation
- T :
-
Kelvin temperature
- vs :
-
Water vapour
- w :
-
Water
- λ :
-
Thermal conductivity
- θ :
-
Volumetric content
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Acknowledgments
This presented work is supported by the Shaanxi Provincial Science and Technology Integrated Innovation Project (No.2012KTCQ03-01).
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Wang, J., Deng, J., Zheng, J. et al. Thermal Conductivity of Loess: Experimental Studies and Empirical Model. KSCE J Civ Eng 28, 644–654 (2024). https://doi.org/10.1007/s12205-023-0773-x
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DOI: https://doi.org/10.1007/s12205-023-0773-x